Series 945 User s Manual

Transcription

1 Series 945 User s Manual TOTAL CUSTOMER SATISFACTION 3 Year Warranty 1/4 DIN Microprocessor-Based Auto-tuning Control Watlow Controls 1241 Bundy Blvd., P.O. Box 5580, Winona, Minnesota USA , Phone: 507/ , Fax: 507/ Rev A August, 1994 Supersedes without change: W945-MA $10.00 Made in the U.S.A. Recycled Paper At Least 10% Postconsumer Waste

2 Contents Starting Out Page Item Chapter 1 3 Starting Out With The Watlow Series General Description Chapter 2 4 How To Install And Wire The Series Installation Procedure 4 Dimensional Information 5 Wiring the Series Sensor Installation Guidelines 6 Input Wiring 7 Output 1 Wiring 8 Output 2 Wiring 9 Alarm Wiring 10 Retransmit Wiring 11 System Wiring Examples Chapter 3 12 How To Use The Keys And Displays 12 Series 945 Keys and Displays Chapter 4 13 How To Setup The Series How to Set the DIP Switch 13 Entering Setup Menu 14 Setup Parameters 17 Setup Menu Table 18 Operation Parameters 20 Operation Menu Table Chapter 5 21 How To Tune And Operate 21 Auto-tuning 22 Manual Tuning 23 Manual and Automatic Operation 24 Changing the Position of an Alarms Jumper 25 Using Alarms 26 Error Code Messages 27 Error Code Actions 28 Appendix 1 28 Noise Sources 28 Decreasing Noise Sensitivity 29 Eliminating Noise 30 Checking For Ground Loops 30 Noise Suppression Devices Available 31 Line Filtering Configurations For Controls 32 Appendix 2 32 Entering the Calibration Menu 33 Restoring Factory Calibration 35 Calibration Procedures 39 Glossary 41 Index 42 Specifications 43 Model Number Information 43 Returns 43 Warranty Notes Informational notes alert you to important details. When you see a note icon, look for an explanation in the margin. or Safety Information Boldface safety information protects both you and your equipment. Please be attentive to them. Here are explanations: The WARNING symbol in the wide text column alerts you to a "WARNING," a safety hazard which could affect you and the equipment. A full explanation is in the narrow column on the outside of the page. ç The CAUTION symbol in the wide text column alerts you to a "CAUTION," a safety or functional hazard which could affect your equipment or its performance. A full explanation is in the narrow column on the outside of the page. 2 WATLOW Series 945 User's Manual Technical Assistance If you encounter a problem with your Watlow control, review all of your configuration information to verify that your selections are consistent with your application... Inputs, Outputs, Alarms, Limits, etc. If the problem persists after checking the above, you can get technical assistance by dialing: An Application Engineer will discuss your problem with you. Please have the following information available: Complete model number Serial Number All configuration information User's Manual The model and serial numbers can be found on the outside of the case. Your Feedback Your comments or suggestions on this manual are welcome, please send them to: Technical Writer, Watlow Controls, 1241 Bundy Blvd., P.O. Box 5580, Winona, MN , or phone 507/ The Watlow Series 945 User's Manual and integral software are copyrighted by Watlow Winona, Inc., 1989, with all rights reserved. blr0392 How to Use the Manual

3 Chapter 1 The Watlow Series 945, A Microprocessor-Based Control Starting Out Starting Out Single Input - Type J, K, T, N, R, S, B, C or Pt2 Thermocouple, RTD or Process Dual Outputs - PID or ON/OFF, User Selectable Output 1 - Heat or Cool Remote Set Point Input - 0-5VDC or 4-20mA Dual Alarms Output 2 - Heat, Cool or None Retransmit Output Up to 10 Slaves Figure 1 - Series 945 Input and Output Overview RS-422A, RS423A RS-232C compatible, or EIA-485 Optional Computer Interface Process Output 1 Auto-tuning Heat only Set Point Output 1 or 2 Percent Power General Description Welcome to the Watlow Series 945, a 1/4 DIN microprocessor-based temperature control. It has a single input, remote set point input, dual output, and dual alarm. The 945 is an auto-tuning control when Output 1 is in the heat mode, and features Automatic/Manual capability with bumpless transfer. In the Auto mode, the 945 has closed loop control with sensory feedback, while the Manual mode has open loop control with user defined output power level. The 945 accepts a variety of thermocouples, as shown above, along with RTD, or process input. The primary output is heat or cool, while the secondary output can be heat, cool or none. An optional retransmit output is offered in place of one of the alarms. Selectable as retransmit of set point or process variable. Units with communications feature data logging with user selectable table, chart or SPC Statistical Process Control printout of data. With the Series 945 you can select either PID or ON/OFF for Output 1 or 2. Input a complete set of PID parameters for both outputs, including proportional band, reset/ integral and rate/derivative. By setting either output's proportional band to zero, the Series 945 becomes a simple ON/OFF control with the switching differential selectable under the HYS hysteresis parameter in the Setup menu. Operator-friendly features include automatic LED indicators to aid in monitoring and setup, as well as a calibration offset at the front panel. The Watlow Series 945 automatically stores all information in a non-volatile memory. Getting Started, Chapter 1 WATLOW Series 945 User's Manual 3

4 Installation Chapter 2 How to Install and Wire the Series Make a panel cutout per the dimensions given below. Your panel thickness can be from 0.06" to 0.25" 1.52 to 6.35 mm. 3.62" to 3.65" sq. 92 to mm 0.92" 23 mm 6.0" 152 mm Figure 2 - Series 945 Panel Cutout and Unit Dimensions Panel Cutout 3.63" X 3.63" X mm 3.8" sq. 97 mm 3.6" ± 0.015" 90 mm ± Bezel 0.17" sq. Dimension 4 mm 2. Remove the 945 from its case by turning the front panel screw 90 counterclockwise CCW. Grip the bezel firmly and pull the control out of the case. Figure 3 - How to Open the Series 945.!! CAUTION: The front panel screw turns 90 only. Do not apply excessive force or turn the screw more than 90. LOCK 3. Place the case in the cutout you just made. Attach the two mounting brackets, shipped with your unit, either to the top and bottom, or to both sides of the unit. Tighten the brackets securely against your panel. Panel Figure 4 - Mounting the Series 945 Case. Mounting Bracket 4. Insert the control chassis into its case and press the bezel to seat it. Turn the front panel screw 90 clockwise CW to lock the control in place. 4 WATLOW Series 945 User's Manual Install and Wire, Chapter 2

5 How to Wire the Series 945 Power Wiring The Series 945 wiring is illustrated by model number option. Check the terminal designation sticker on the control and compare your model number to those shown here and also the model number breakdown on the inside back cover of this manual. Series 945 internal circuits appear "inside" the line drawing of the 945, while connections and terminal designations appear "outside" the line drawing. All outputs are referenced to a de-energized state. The final wiring figure is a typical system example. When you apply power without a sensorinput on the terminal strip, the 945 displays " " in the upper display, and "0" in the lower display. Press AUTO/ MAN twice, and ER 7 is displayed for one second. This error indicates an open sensor or A/D error. Remove power to the control and connect the sensor properly, see Page 6. All wiring and fusing must conform to the National Electric Code and to any locally applicable codes as well Fuse L1 L2 Earth Ground Figure VAC Power Wiring 120 VAC Fuses L1 L2 Figure VAC Power Wiring Earth Ground Sensor Installation Guidelines 240 VAC We suggest you mount the sensor at a location in your process or system where it reads an average temperature. Choose a point that will adequately represent the process temperature without being overly reactive. For thermocouple inputs: Use an isolated or ungrounded thermocouple if an external 4-20mA output device with a non-isolated circuit common is connected. Extension wire must be of the same alloy as the thermocouple itself to limit errors. WARNING: To avoid potential electric shock, use National Electric Code NEC safety practices when wiring and connecting this unit to a power source and to electrical sensors or peripheral devices. For RTD inputs: There could be a +2 F input error for every 1 of lead length resistance when using a 2 wire RTD. That resistance, when added to the RTD element resistance, will result in erroneous input to the instrument. To overcome this problem, use a 3 wire RTD sensor, which compensates for lead length resistance. When extension wire is used for a 3-wire RTD, all wires must have the same electrical resistance i.e. same gauge, copper stranded. For 0-5VDC or 4-20mA process inputs: The rl and rh settings scale the display to match the measured range of the process signal. For 0-5VDC process input, the impedance is 100KΩ. For 4-20mA process input, the impedance is 249Ω. Install and Wire, Chapter 2 WATLOW Series 945 User's Manual 5

6 Input Wiring Thermocouple Input Figure 7 - Thermocouple Input Wiring 945A - 1 _ - _ A - 2 _ - _ A - 3 _ - _ A - 4 _ - _ = Red RTD, 2 or 3 Wire Jumper #5 to #6 for 2 Wire RTD Figure 8-2 or 3 wire RTD Input Wiring. 945A - 2 _ - _ A - 3 _ - _ These input connections are also used in conjunction with T/C and RTD sensor types when using the remote set point input. 0-5VDC Process or Remote Set Point Input 1 + Figure VDC Process Input Wiring. 945A - 2 _ - _ A - 3 _ - _ V DC Input impedance: 100KΩ 4-20mA Process or Remote Set Point Input Figure mA Process Input Wiring. 945A - 2 _ - _ A - 3 _ - _ IDC + - A jumper must be installed between Terminal #2 and mA process input: 249Ω. 6 WATLOW Series 945 User's Manual Install and Wire, Chapter 2

7 Output 1 - Solid State Relay With Contact Suppression Output 1 Wiring 945A - _ B - _ 000 Figure 11 - Solid State Relay With Contact Suppression Suppression 17 N.O. External Load L2 Off Off state state impedance: impedance: 20K 31MΩ max. max. 18 COM. Fuse L1 Output 1 - Switched DC Output Open Collector Figure 12 - Switched DC Open Collector 945A - _ C - _ 000 Switched DC, Open Collector, Non-Isolated Logic Switch External Load NOTE: Minimum load resistance is 500. Available current is 22mA maximum. Typical voltage drop across a 1K load is 12 to 19 volts. Output 1 - Mechanical Relay, 6 Amp, Form C Figure 13-6 Amp Mechanical Relay 945A - _ D - _ 000 Mechanical Relay, Form C, 6 Amp Off state impedance: 20KΩ min. Output 1 - Process, 4-20mA 16 COM. 17 N.O. 18 N.C. Fuse External Load L1 L2 NOTE: This output is supplied with an arc suppression snubber across the output terminals. High impedance loads may remain energized even though the output device is turned OFF. 945A - _ F - _ 000 Process, 4-20 ma, Non-Isolated I DC External Load Figure 14 - Process, 4-20mA Load impedance: 600Ω max. Install and Wire, Chapter 2 WATLOW Series 945 User's Manual 7

8 Output 1 & 2 Wiring Output 1 - Process, 0-5VDC 945A - _ H - _ 000 Figure 15 - Process, 0-5VDC External Load Load impedance: 10KΩ min. Figure 16 - Solid State Relay Without Contact Suppression Output 1 - Solid State Relay Without Contact Suppression 945A - _ K - _ 000 Solid State Relay, Form A, 0.5 Amp Figure 17 - Solid State Relay With Contact Suppression Off state impedance: 31MΩ max N.O. COM. External Load Fuse Output 2 - Solid State Relay With Contact Suppression L2 L1 NOTE: This output is supplied with an arc suppression snubber across the output terminals. High impedance loads may remain energized even though the output device is turned OFF. NOTE: Minimum load resistance is 500Ω. Available current is 22mA maximum. Typical voltage drop across a 1KΩ load is 12 to 19 volts. Figure 18 - Switched DC Output Open Collector 945A - B _ - _ 000 Suppression Off state impedance: 20KΩ max. Switched DC, Open Collector, 945A - C _ - _ 000 Non-Isolated N.O. COM. Fuse External Load Output 2 - Switched DC Output Open Collector Logic Switch Load impedance: 10KΩ min. + - External Load L1 L2 8 WATLOW Series 945 User's Manual Install and Wire, Chapter 2

9 Output 2 - Mechanical Relay, 6 Amp, Form A Output 2 & Alarms 945A - D _ - _ 000 Suppression 14 N.O. External Load L2 Figure 19-6 Amp Mechanical Relay 15 COM. L1 Fuse Off state impedance: 20KΩ min. Output 2 - Solid State Relay Without Contact Suppression 945A - K _ - _ 000 Solid State Relay, Form A, 0.5 Amp Fuse 14 N.O. L1 NOTE: This output is supplied with an arc suppression snubber across the output terminals. High impedance loads may remain energized even though the output device is turned OFF. Off state impedance: 31MΩ max. 15 COM. External Load L2 Figure 20 - Solid State Relay Without Contact Suppression For more information on alarms and alarm jumper selection, see Chapter 5. Alarm Output - Mechanical Relay, 6 Amp, Single Form A or B 945A- _ 1 - _ 000 Suppression Output #3 Off state impedance: 20KΩ min Fuse Load L1 L2 Figure 21 - Alarms Option 1 Wiring. Alarm Output - Mechanical Relay, 6 Amp, Dual Form A or B 945A- _ 2 - _ 000 Output #4 Output #3 Suppression Off state impedance: 20KΩ min Fuse Load Fuse Load Figure 22 - Alarms Option 2 Wiring. Install and Wire, Chapter 2 WATLOW Series 945 User's Manual 9 L1 L2 L1 L2

10 Alarm/Retransmit Mechanical Relay, 6 Amp, Form A or B/0-5VDC Retransmit Figure 23 - Alarm/Retransmit Option 3 Wiring. NOTE: This output is supplied with an arc suppression snubber across the output terminals. High impedance loads may remain energized even though the output device is turned OFF. 945A- _ 3 - _ Fuse Load External Load Load impedance: 10KΩ min. for 0-5VDC. Relay offstate impedance: 20KΩ. Mechanical Relay, 6 Amp, Form A or B/4-20mA Retransmit - + L1 L2 Figure 24 - Alarm/Retransmit Option 4 Wiring. 945A- _ 4 - _ IDC Fuse Load External Load L1 L2 Load impedance: 10K min. for 4-20mA. Relay offstate impedance: 20K. 0-5VDC Retransmit Output Figure 25 - Retransmit Option 5 Wiring. Process, 945A- _ 0-5VDC 5 - non-isolated _ External Load Load impedance: 10KΩ min. 4-20mA Retransmit Output 945A- _ 6 - _ 000 Figure 26 - Retransmit Option 6 Wiring. IDC External Load Load impedance: 600Ω max. 10 WATLOW Series 945 User's Manual Install and Wire, Chapter 2

11 WARNING: All wiring and fusing must conform to the National Electric Code NFPA70 and to any locally applicable codes. Contact your local board for additional information. Failure to observe NEC safety guidelines could result in injury to personnel. ç CAUTION: Watlow mercury relays are designed to be used only with resistive loads. Wiring Example Figure 27 - System Wiring Example L1 L2 120 VAC Earth Ground 945A-2DD0-A000 Rear View Fuse 140A-16XX-6000 High Limit Control Ground Red COM N.O. Mercury Relay for Control Normally Open Momentary Switch High Limit Mechanical Contactor Coil ç Heater Limit Sensor Process Sensor 945A-2DD0-A000 Terminal Function , , Jumper to , S1 5 S2 6 S3 7 T.C. + 8 Not Used 9 T.C L1 240V 11 L1 120V 12 L2 13 Earth Ground 14 N.O. Output #2 15 Com. 16 Com. 17 N.O. Output #1 18 N.C L A-2DD0-A A Series 945 Temperature Control CR 2 Hg 1 8 L1 L2 2 9 Reset 10 Series 140 COM Limit 11 Control TC + 12 TC - N.O. 2CR COM N.C. R 15 2 Hi Temp. Light Hg Heater CR-1 2CR L2 Install and Wire, Chapter 2 WATLOW Series 945 User's Manual 11

12 Keys/Displays Chapter 3 Figure 28 - Series 945 Keys and Displays. How to Use the Keys and Displays After 1 minute with no key activations, the control reverts to the process value in the upper display and the set point in the lower display. Upper Display Red, 0.56" 14 mm high, seven segment, four digit LED display, indicating either process actual temperature, the operating parameter values, or an open sensor. When powering up, the Process display will be blank for 8 seconds. Lower Display Red 0.56" 14 mm high, seven segment, four digit LED display, indicating the set point, operation parameters, menu parameters, and error or alarm codes. L 1 & L2 When lit, these LED's tell you when Output 1 or Output 2 is energized. L2 only appears if your unit has the #2 output hardware. A1 & A2 When lit, these LEDs tell you when Alarms 1 or 2 are active. Only appears on those units with alarms option. MODE Key Steps the control through the Operating menu; also, in the Auto mode, enters new data selected. UP Key Increases the value of the displayed parameter. A single touch increases the value by one. Hold the key down to increase the value at a rapid rate. New data is self entering in 5 seconds. DOWN Key Decreases the value of the displayed parameter. A single touch decreases the value by one. Hold the key down to decrease the value at a rapid rate. New data is self entering in 5 seconds. AUTO/MAN Key Pressed once, it clears any latched alarms. If the key is pressed again within 5 seconds, the control toggles between the Auto and Manual mode. While in the Manual mode, percent power is always displayed in the lower display. Front Panel Locking Screw Secures or releases the control chassis from its case. UP/DOWN keys When pressed simultaneously for 3 seconds, the Setup Menu appears displaying the LOC parameter. At the LOC parameter, continue to press the UP/DOWN keys simultaneously, and the Calibration Menu will appear. Auto/Manual LED Lit when the control is in Manual operation. Press the key twice to enter Auto operation. A blinking Auto/Manual LED indicates that pressing the AUTO/MAN key toggles between Auto and Manual. After 5 seconds without pressing the AUTO/MAN key, the LED stops blinking, and returns to its previous state. 12 WATLOW Series 945 User's Manual Keys and Displays, Chapter 3

13 Chapter 4 How To Setup The Series 945 Setup Setting up the Series 945 is a simple process. First configure the 945's features to your application in the Setup Menu, and then enter values in the Operating Menu. Use the MODE key to move through the menus and the UP/DOWN keys to select data. At this point, enter the Calibration menu by pressing the UP/DOWN keys simultaneously for 3 seconds. Selecting US or SI under the dfl parameter determines the following: If selected as US, rate, reset, F and proportional band in degrees will appear. If selected as SI, integral, derivative, C and proportional band in % of span will appear. See Appendix II to change this parameter. How to Set the DIP Switch The Watlow Series 945 has a Dual In-line Package DIP switch inside the control on the A circuit board middle board. The location of the board and switches appear below. The switches are clearly numbered. When Switch #1 is ON, the Setup parameters can be viewed but not changed. Switch #2 is not used. The factory default is OFF. A Figure 29 - DIP Switch Location and Orientation 1 Hardware Lockout of SETUP Parameters 2 Battery Not UsedDischarge for Storage Factory default is OFF Control Chassis - Top View Entering the Setup Menu Enter the Setup Menu by pressing the UP/DOWN keys simultaneously for 3 seconds. The lower display shows the LOC parameter, and the upper display shows its current level. All keys are inactive until you release both keys. You can reach the LOC parameter from anywhere. You will not see all parameters in this menu, depending on the unit's configuration and model number. After stepping through the menu it returns to the control set point parameter under the Operation menu. Figure 30 - Entering the Setup Menu Setup, Chapter 4 WATLOW Series 945 User's Manual 13

14 Setup Menu Figure 31 - The Setup Menu NOTE: The rl and rh parameters are used to scale the display for process inputs, and/or will scale the retransmit range for process output. rl and rh also limit the range of the set point. M 75 [Set Point] LOC In rsp User lock out Input type Remote set point dec C _ F rl rh Ot 1 HYS1 Ot 2 HYS2 AL 1 LAt1 HYS3 Ot4 Decimal place Celcius_Fahrenheit Range low Range high Output 1 Hysteresis 1 Output 2 Hysteresis 2 Alarm 1 Latching for alarm 1 Hysteresis 3 Output 4 AL 2 LAt2 Alarm 2 Latching for alarm 2 Setup Parameters = Parameter may or may not appear depending on control configuration. = Only appear if your unit has communications. See the Series 945 data communications manual for more information on these parameters. HYS4 SIL rtd baud data Prot Addr Log LSL USL LinE YEAr Mon day HOUr Int tag Min Hysteresis 4 Silence alarm RTD calibration curve Baud rate Data bits and parity Protocol type Address Logging printout Lower spec limit Upper spec limit tbs Time base Lines per page Current year Current month Current day Real time hour Real time minutes Time interval Variables to transmit LOC 14 WATLOW Series 945 User's Manual When you are at the top of the menu, the Series 945 displays the user level of operation in the upper display, and the LOC parameter in the lower display. Press the MODE key and the value of the next parameter appears in the upper display, the prompt appears in the lower display. For units with process input, see the L-r parameter on Page 20 for how LOC is affected. Lock: Selects the level of operator lockout. Range: 0-3 Default: 0 LOC 0: All operating parameters may be viewed or changed. Manual operation is permitted. Bumpless transfer to manual operation can occur on sensor break. LOC 1: The set point, actual, and L-r if rsp is enabled are the only visible parameters, set point is adjustable in this level. Manual operation is permitted. Bumpless transfer to manual operation can occur on sensor break. LOC 2: The set point, actual, and L-r if rsp is enabled are the only visible parameters, set point is adjustable in this level. Manual operation is not permitted. Bumpless transfer is defeated, outputs are disabled on sensor break. LOC 3: The set point and actual are the only visible parameters, set point is not adjustable in this level of lockout. Manual operation is not permitted. Bumpless transfer is defeated, outputs are disabled on sensor break. Setup, Chapter 4

15 Setup Input: Selects the sensor input type. Only those input types which are compatible with your unit will appear. See the model number information for your type. Range: J, K appears as H, t, n, c, r, S, b, Pt2, rtd, rt.d, 0-5, 420 Default: J or r Remote Set Point: Enables models with process input capability to accept a remote set point signal from another device. This parameter only appears if In = Thermocouple or RTD. Range: OFF, 0-5, 420 Default: OFF Decimal: Selects the location of the decimal point for all process related data. This parameter only appears if the In parameter is 0-5 or 420. Range: 0, 0.0, 0.00 Default: 0 Celsius _ Fahrenheit: Selects the units of temperature measurement. This parameter only appears if the In parameter is a thermocouple or RTD input. Dependent on the dfl parameter. See Appendix II. Range: C or F If dfl = US: Default: C If dfl = SI: Default: F Range Low: Selects the low end of the set point range. See the model number and specification information on the inside back cover, and Table 1 on Page 16 for sensor range values. Also used to set the low end of the process or remote set point input and/or the low end of the range for the retransmit output. 0.0VDC and 4mA represent Range Low rl for process inputs and outputs. The process input and retransmit output are linearly scaled between rl and rh. Range: Sensor range low to rh Default: Low limit of sensor type Range High: Selects the high end of the set point range. See the model number and specification information on the inside back cover, and Table 1 on Page 16 for your sensor range values. Also used to set the high end of the process or remote set point input and/or the high end of the range for the retransmit output. 5.0 VDC and 20mA represent Range High rh for process input and output. The process input and retransmit output are linearly scaled between rl and rh. Range: Sensor range high to rl Default: High limit of sensor type Output 1: Selects the output action for the primary output. Action is in response to the difference between set point and process variable. Select ht heat for reverse acting or select CL cool for direct acting. Range: ht, CL Default: ht Hysteresis 1: Selects the switching hysteresis for Output 1 when Pb1 = 0 ON/ OFF. See Page 18 for the Pb1 parameter. Range: 1 F - 99 F 0.1 F F Default: 3 F/0.3 F 1 C - 55 C 0.1 C C 1 Unit - 99 Units 0.1 Units Units Output 2: Selects the output action for the secondary output. Action in response to the difference between set point and process variable. Select ht heat for reverse acting or select CL cool for direct acting. This parameter only appears if you have a secondary output. Range: CL, ht, no Default: CL In rsp dec C _ F rl rh Ot1 HYS1 Ot2 Hysteresis 2: Selects the switching hysteresis for Output 2 when Pb2 = 0 ON/OFF. See Page 18 for the Pb2 parameter. This parameter only appears if you have a secondary output; it will not appear if Ot2 = no. Range: 1 F - 99 F 0.1 F F Default: 3 F/0.3 F 1 C - 55 C 0.1 C C 1 Unit - 99 Units 0.1 Units Units HYS2 Setup, Chapter 4 WATLOW Series 945 User's Manual 15

16 Setup AL1 LAt1 HYS3 Ot4 Alarm 1: Determines whether the alarm type for Alarm 1 is process, deviation, or none. A process alarm is set at an absolute temperature. A deviation alarm follows or tracks the set point. This parameter only appears if your unit has alarms. Range: Pr, de, no Default: Pr Latching 1: Selects whether Alarm 1 is latching or non-latching. Latching alarms must be cleared before the alarm output will reset. Non-latching automatically resets the alarm output when the condition clears. This parameter will not appear if AL 1 = no, or your unit does not have alarms. Range: LAt or nla Default: nla Hysteresis 3: Selects the switching hysteresis for Alarm 1. Appears if your unit has alarms and AL 1 = Pr or de. Range: 1 F - 99 F 0.1 F F Default: 3 F 1 C - 55 C 0.1 C C 1 Unit - 99 Units 0.1 Unit Units Output 4: Selects Output 4 as retransmit of Process PrOC or Set Point StPt. Hardware must be present. Scaling of the retransmit output is determined by rl and rh. Range: PrOC, StPt, no Default: PrOC Table 1 - Input Ranges. AL2 LAt2 HYS4 SIL rtd 16 WATLOW Series 945 User's Manual Alarm 2: Determines whether Alarm 2 type is process, deviation, or none. A process alarm is set at an absolute temperature. A deviation alarm follows or tracks the set point. This only appears if your unit has alarms. Range: Pr, de, no Default: Pr Latching 2: Selects whether Alarm 2 is latching or non-latching. Latching alarms must be cleared before the alarm output will reset. Non-latching automatically resets the alarm output when the condition clears. Will not appear if your unit does not have alarms or AL2 = no. Range: LAt or nla Default: nla Hysteresis 4: Selects the switching hysteresis for Alarm 2. Appears if your unit has alarms and AL 2 = Pr or de. Range: 1 F - 99 F 0.1 F F Default: 3 F 1 C - 55 C 0.1 C C 1 Unit - 99 Units 0.1 Unit Units Silencing: Selects alarm silencing inhibit for Alarm 1. This parameter only appears when AL1 = de. For more information see Chapter 5. Range: On or OFF Default: OFF RTD: Selects the RTD calibration curve for RTD inputs. Appears if In = rtd or rt.d. JIS = Ω/Ω C, DIN = Ω/Ω C. Range: din or JIS Default: din Any parameters that appear after RTD are related to data communications. See How to Use Data Communications with the Watlow Series 945 for more information. Input Type Sensor Range Low Sensor Range High J 32 F/0 C 1382 F/750 C K appears as H -328 F/-200 C 2282 F/1250 C t -328 F/-200 C 662 F/350 C n 32 F/0 C 2282 F/1250 C c 797 F/425 C 4200 F/2315 C Pt2 32 F/0 C 2543 F/1395 C r 32 F/0 C 2642 F/1450 C S 32 F/0 C 2642 F/1450 C b 1598 F/870 C 3092 F/1700 C rtd F/-200 C 1112 F/600 C rt.d F/-99.9 C F/200.0 C 0-5 VDC -5.00/-50.0/ /350.0/ ma -5.00/-50.0/ /350.0/3500 Setup, Chapter 4

17 Setup Setup Menu Use this page as a master copy for configuring your Series 945. Do not enter any values here; make photocopies instead. Table 2 - Setup Menu Prompts and Descriptions. Parameter Value Range Factory Default Appears If: LOC In J, K appears as H, t, n, c, Pt2, J or r r, S, b, rtd, rt.d, 0-5, 420 rsp OFF, 0-5, 420 OFF In = T/C or RTD dec 0, 0.0, or In = 0-5 or 420 C _ F C or F F In = T/C or RTD rl rl to rh Input dependent. rh rh to rl Input dependent. Ot1 ht or CL ht HYS1 1 F - 99 F, 1 C - 55 C, 1U - 99U 3 F 0.1 F F, 0.1 C C, 0.1U - 9.9U Ot2 ht, CL or no CL Unit has secondary output HYS2 1 F - 99 F, 1 C - 55 C, 1U - 99U 3 F Unit has secondary output 0.1 F F, 0.1 C C, 0.1U - 9.9U Ot2 = ht or CL AL1 Pr, de or no Pr Unit has alarms LAt 1 LAt or nla nla Unit has alarms and AL1 = Pr or de HYS3 1 F - 99 F, 1 C - 55 C, 1U - 99U 3 F Unit has alarms and 0.1 F F, 0.1 C C, 0.1U - 9.9U AL1 = Pr or de Ot4 no, PrOC, StPt PrOC Hardware is present AL 2 Pr, de or no Pr Unit has alarms LAt 2 LAt or nla nla Unit has alarms and AL2 = Pr or de HYS4 1 F - 99 F, 1 C - 55 C, 1U - 99U 3 F Unit has alarms and 0.1 F F, 0.1 C C, 0.1U - 9.9U AL2 = Pr or de SIL On or OFF OFF Unit has alarms & AL1 = de rtd JIS or din din In = rtd or rt.d Setup, Chapter 4 WATLOW Series 945 User's Manual 17

18 Operation Operation Menu In the Operation menu, the 945 operates as a digital set point control. All outputs are turned OFF when set point is set to OFF. NOTE: The upper display will always return to the process value after 1 minute without key strokes. = Parameter may not appear depending on control configuration = Only appears if your unit has communications. See the Series 945 data communications manual for more information. M Mode Key Figure 32 - The Operation Menu 75 SP2 Pb1 Pb2 re1/it1 re2/it2 ra1/de1 ra2de2 [Control Set Point or Remote Set Point ] Set point 2 Proportional band 1 Proportional band 2 Reset 1/Integral 1 Reset 2/Integral 2 Rate 1/Derivative 1 Rate 2/Derivative 2 Ct1 Ct2 db A1LO A1HI A2LO A2HI CAL AUt Cycle time 1 Cycle time 2 Dead band Alarm 1low Alarm 1 high Alarm 2 low Alarm 2 high Calibration offset Auto-tune CLUP Control limit update L - r Local-remote 75 SP2 Pb1 Pb2 Operation Parameters Set Point 1 or Remote Set Point 1: Sets the operating set point for the control outputs. Appears if L-r = L, see Page 20. If L-r = R, this parameter represents the remote set point. Range: OFF / rl to rh Default: Dependent on input range Set Point 2: Sets the operating set point for Output 2 when control mode is ht/ht or CL/CL. Appears when Ot1 and Ot2 are the same, and functions as an ON/OFF control. Range: rl to rh Default: Same as primary set point. Proportional Band: Expressed in degrees, process units or % of span, within which a controller proportioning function is active for Output 1 or 2. When PbX = 0, it functions as an ON/OFF control. The switching differential is then determined by the corresponding HYSX parameter. Pb1 is always visible. Pb2 will not appear if your unit does not have Output 2, Ot2 = no, or Ot2 is the same value as Ot1. Also dependant on the dfl parameter in the Calibration menu. If dfl = US: Range: 0 to 999 F/0 to 555 C/0 to 999 Units; 0.0 to 9.9 F/0.0 to 5.5 C/ 0.0 to 9.9 Units Defaults: Pb1 = 25 F/2.5 F Pb2 = 0 If dfl = SI: Range: 0 to 999.9% of span Defaults: Pb1 = 3.0% Pb2 = 0.0% 18 WATLOW Series 945 User's Manual Setup, Chapter 4

19 Operation Reset/Integral1: A reset integral control action for Output 1 or Output 2 automatically eliminating offset, or "droop," between set point and actual process temperature. Will not appear if your unit does not have a secondary output. re1/it1: Will not appear if Pb1 = 0. re2/it2: Will not appear if Pb2 = 0, Ot2 = no, or Ot2 is the same configuration as Ot1. Either reset re or integral It will appear depending on how the dfl parameter is set in the Calibration menu. See Appendix II. If dfl = US: Range: 0.00 to 9.99 repeats/minute Default: 0.00 If dfl = SI: Range: 00.1 to 99.9 minutes per repeat Default: 0.00 Rate/Derivative 1: The rate derivative function for Output 1 or Output 2. Rate or derivative is used to eliminate over shoot on start up, or after the set point changes. ra1/de1: Will not appear if Pb 1 = 0. ra2/de2: Will not appear if your unit does not have a secondary output, Pb2 = 0, Ot2 = no, or Ot2 is the same value as Ot1. Either rate ra or derivative de will appear depending on how dfl is set in the Calibration menu. If dfl = US or SI: Range: 0.00 to 9.99 minutes Default: 0.00 Cycle Time 1 & 2: Time for a controller to complete one ON/OFF cycle for Output 1or Output 2; expressed in seconds. Ct1: Will not appear if Pb 1 = 0, or Output 1 is 4-20mA. Ct2: Will not appear if your unit does not have a secondary output, Pb2 = 0, Ot2 = no, or Ot2 is the same value as Ot1. Range: 1 to 60 seconds Default: 5 Dead Band: The area between Output 1 and 2 where no heating or cooling takes place in a heat/cool proportional control. Only appears if your unit is set up as a ht/cl or CL/ht unit. Range: ±0 to 99 F/0 to 55 C/0 to 99 Units; or ±0.0 to 9.9 F/0.0 to 5.5 C/0.0 to 9.9 Units Default: 0 Alarm 1 Low: Represents the low process alarm or low deviation alarm for Alarm 1. Will not appear if your unit does not have alarms and AL 1 = no. If AL 1 = de: Range: 0 to -999 F/0 to -999 C/0 to -999 Units Default: -999 F If AL 1 = Pr: Range: rl to A1HI Default: rl Alarm 1 High: Represents the high process alarm or high deviation alarm for Alarm 1. Will not appear if your unit does not have alarms and AL 1 = no. If AL 1 = de: Range: 0 to 999 F/0 to 999 C/0 to 999 Units Default: 999 F If AL 1 = Pr: Range: A1LO to rh Default: rh Alarm 2 Low: Represents the low process alarm or low deviation alarm for Alarm 2. Will not appear if your unit does not have Alarm 2 and AL 2 = no. If AL 2 = de: Range: 0 to -999 F/0 to -999 C/0 to -999 Units Default: -999 F If AL 2 = Pr: Range: rl to A2HI Default: rl Alarm 2 High: Represents the high process alarm or high deviation alarm for Alarm 2. Will not appear if your unit does not have Alarm 2 and AL 2 = no. If AL 2 = de: Range: 0 to 999 F/0 to 999 C/0 to 999 Units Default: 999 F If AL 2 = Pr: Range: A2LO to rh Default: rh Calibration Offset: Adds or subtracts degrees from the input signal. Range: -180 F to 180 F/-100 C to 100 C/-180Units to 180 Units; or F to F/ C to C Default: 0 re1/it1 re2/it2 ra1/de1 ra2/de2 Ct1 Ct2 db A1LO A1HI A2LO A2HI CAL Setup, Chapter 4 WATLOW Series 945 User's Manual 19

20 Operation AUt L-r Table 3 - Operation Menu Prompts and Descriptions. Auto-Tune: Initiates auto-tune for Output 1. This parameter appears if Ot 1 =ht. Range: 0 = off, 1 = slow, 2 = medium, 3 = fast Default: 0 Local-Remote: Selects a local or remote set point for the Series 945. This parameter only appears if the LOC parameter = 0, 1 or 2, and rsp = 0-5 or 420. If L-r = r, the remote set point will be displayed in place of the internal set point. Range: L = Local operation r = remote operation Default: L Operation Menu Use this page as a master copy for your Series 945 Operation parameters. Do not enter any values here; make photocopies instead. Parameters Value Range Factory Default Appears If: Set Point 1 or rl to rh 75 F Remote Set Point 1 SP2 rl to rh Primary set point. Ot1 = Ot2, Pb1 = 0 Pb1 If dfl = US: F/0-555 C/0-999U 25 F/2.5 F F/ C/0-99.9U 0=ON/OFF control. HYS1 =swtch. diff. If dfl = SI: 0 to 999.9% of span 3%/.3% Pb2 Same as Pb1. 0 F Ot2 = ht or CL Ot2 Ot1 re1/it1 If dfl = US: 0.00 to 9.99 repeats/min rpt/min. Pb = No Reset. If dfl = SI: 00.1 to 99.9 min./repeat 0.00 re2/it2 Same as re1/it rpt/min. Pb2 0, Ot2 Ot1 Ot2 = ht or CL ra1/de to 9.99 min min. Pb = No Rate. ra2/de2 Same as ra1/de min. Pb2 0, Ot2 Ot1 Ot2 = ht or CL Ct1 1 to 60 seconds 5 seconds Pb1 0, Output1 420 Ct2 1 to 60 seconds 5 seconds Pb2 0, Ot2 Ot1, Ot2 = ht or CL db ±0-99 F/±0-55 C/0-99U. 0 Ht/CL or CL/Ht ± F/ C/ U A1LO Deviation de -999 to AL1 = Pr, de Process Pr rl to A1HI rl Unit has alarms A1HI Deviation de 0 to AL1 = Pr, de Process Pr A1LO to rh rh Unit has alarms A2LO Deviation de -999 to AL2 = Pr, de Process Pr rl to A2HI rl Unit has Alarm 2 A2HI Deviation de 0 to AL2 = Pr, de Process Pr A2LO to rh rh Unit has Alarm 2 CAL ±180 F/±100 C/±180U 0 AUt Ot1 = ht, L-r = L L-r L or r L rsp = 0-5 or WATLOW Series 945 User's Manual Setup, Chapter 4

21 Tuning Chapter 5 How to Tune and Operate Auto-tuning Auto-tuning applies to Output 1, heating only. The auto-tuning procedure operates on a thermal response value slow, medium, or fast. Use the slow thermal response when your process does not reach set point too rapidly, or if it usually does not exceed set point a lot. A fast thermal response produces a rapid temperature change over a short period of time. Once the auto-tune sequence has begun, the Output 1 heat proportional band is set to 0 and the control goes into an ON/OFF mode of control at 90% of the established set point. The displayed set point remains unchanged. The cool output remains off for the tuning duration. Once the control learns the thermal system response, it returns to a standard PID control using the PID values automatically set as a result of auto-tuning. Output 2 cool PID values are unaffected by auto-tuning, and remain at their factory default settings. See Manual tuning on the next page to set cool PID parameters. Any change of the set point, while in auto-tune, re-initiates the auto-tune procedure. The Series 945 will not Auto-tune while in remote set point. Transferring from local to remote set point takes the 945 out of auto-tune. 200 Auto-tune Begins Auto-tune Complete Set Point 180 Temp % of Set Point Process Figure 33 - Auto-tuning at a Set Point of 200 F. Time In order for the 945 to successfully complete auto-tune, the process must cross set point four times within 80 minutes after auto-tune has started. If this does not happen within the 80 minute time limit, the Pb remains at 0 and the control functions in an ON/OFF mode. Tuning and Operating, Chapter 5 WATLOW Series 945 User's Manual 21

22 Tuning To start auto-tuning: 1. Press the MODE key until the AUt parameter appears in the data display. 2. Select a thermal response value using the UP/DOWN keys, 1=slow, 2=medium, and 3=fast. A thermal response value of 2 satisfactorily tunes most thermal systems. 3. Press the MODE key. While the control is in the tuning mode, the lower display alternately displays the normal information and the prompt At. The time between alternations is 1 second. 4. When tuning is complete, the displays return to their previous state and AUt reverts to 0. The 945 installed appropriate PID tuning parameters and saved them in the non-volatile memory. If a mechanical relay or contactor is switching power to the load, a longer cycle time may be desirable to minimize wear on the mechanical components. Typical life of a mechanical relay is 100,000 cycles. To abort auto-tuning, the operator must reset the AUt parameter to 0, press AUTO/MAN twice, or cycle power off and on. In all cases, aborting auto-tune restores all values to those previous to auto-tuning. Manual Tuning For optimum control performance, tune the Series 945 to your thermal system. The tuning settings here are for a broad spectrum of applications; your system may have somewhat different requirements. NOTE: This is a slow procedure, taking from minutes to hours to obtain optimum value. NOTE: Tune heating outputs at a set point above ambient temperature. Tune cooling outputs at a set point below ambient temperature. 1. Apply power to the Series 945 and enter a set point. Begin with these Operation parameters: Pb = 1, re/it = 0.00, ra/de = 0.00, Ct = 5, CAL = 0, AUt= Proportional Band Adjustment : Gradually increase Pb until the upper display temperature stabilizes to a constant value. The process temperature may not be right on set point because the initial reset value is 0.00 repeats per minute. 3. Reset/Integral Adjustment: Gradually increase re/it until the upper display temperature begins to oscillate or "hunt." Then slowly decrease re/it until the upper display stabilizes again near set point. 4. Cycle Time Adjustment: Set Ct as required. Faster cycle times sometimes achieve the best system control. However, if a mechanical contactor or solenoid is switching power to the load, a longer cycle time may be desirable to minimize wear on the mechanical components. Experiment until the cycle time is consistent with the quality of control you want. Ct will not appear on units with a process output. 22 WATLOW Series 945 User's Manual Tuning and Operating, Chapter 5

23 Tuning/Operation 5. Rate/Derivative Adjustment: Increase ra/de to 1.00 minute. Raise set point by 20 to 30 F, or 11 to 17 C, observe the system's approach to set point. If the load temperature overshoots set point, increase ra/de to 2.00 minutes. Next raise set point by 20 to 30 F, or 11 to 17 C and watch the approach to the new set point. If you increase ra/de too much, approach to set point will be very sluggish. Repeat as necessary until the system rises to the new set point without overshooting or approaching the set point too slowly. 6. Calibration Offset Adjustment: You may want your system to control to a temperature other than the value coming from the input sensor. If so, measure the difference between that temperature perhaps at another point in the system and the process value showing in the upper display. Then enter the CAL offset value you want. Calibration offset adds or subtracts degrees from the value of the input signal. Manual and Automatic Operation To change from manual to auto operation, press AUTO/MAN twice. Manual operation provides open loop control of the outputs from a range of -100% full cooling to 100% full heating power. The 945 allows a negative output value only with a Cl Cool selection on either Ot1 or Ot2. Automatic operation provides closed loop ON/OFF or PID control. When the operator transfers from a closed loop to an open loop, the 945 retains the power level from the closed loop control, referred to as bumpless transfer. When the 945 returns to closed loop control, it restores the previous set point temperature. The LED on the AUTO/MAN key indicates auto or manual operation. When the LED is ON, the control is in manual operation. When the LED is OFF, it is in Automatic operation. When the LED flashes, press the key again within five seconds to complete the change in operation. When a sensor opens the 945 will switch from automatic to manual operation. If LOC = 0 or 1 and the conditions for bumpless transfer are met, process stabilizes within ± 5% of set point within the last two minutes and less than 75% power. The 945 switches to manual operation at the last automatic power level. If LOC = 2 or 3, or the conditions of bumpless transfer have not been met, the 945 switches into manual operation at 0% power outputs disabled. When transferring from auto to manual operation, the control outputs remains stable "bumpless," smooth transition. When transferring from manual to automatic operation, the control outputs may change significantly. In manual operation, the output value appears in the lower display; in automatic operation, the set point appears. Tuning and Operating, Chapter 5 WATLOW Series 945 User's Manual 23

24 Alarm Outputs Changing the Position of an Alarm Jumper 1. Remove power from the control. Turn the front panel screw 90 counterclockwise. 2. Grip the front panel bezel and pull it straight out from the control case. The control chassis will come out of the case as you pull the bezel. 3. Set the jumper to the position you want. See below for jumper location. NOTE: Depending on the unit you order, your control may have 0, 1, or 2 alarm jumpers. 4. Return the control chassis to the case. Be sure you have it oriented correctly. Press firmly, but gently, to seat the chassis. Options Board A Figure 34 - Alarms Jumper Location. A AL1 AL2 N.O. Contacts Form A N.C. Contacts Form B Control Chassis - Top View The alarm output de-energizes upon an alarm or power interruption to the 945's power supply. When you select N.O. Contacts, the contact is open when an alarm occurs. When selecting N.C. Contacts, the contact closes when an alarm occurs. 24 WATLOW Series 945 User's Manual Tuning and Operating, Chapter 5

25 Alarms Using Alarms The Series 945 has two alarm types, Process or Deviation. A Process alarm sets an absolute temperature. When the process exceeds that absolute temperature limit an alarm occurs. The Process alarm set points may be independently set high and low. A Deviation alarm alerts the operator when the process strays too far from set point. The operator can enter independent high and low alarm settings. The reference for the deviation alarm is the set point. Any change in set point causes a corresponding shift in the deviation alarm. Example: If your set point is 100 F, and a deviation alarm set at +7 F as the high limit, and -5 F as the low limit, the high alarm trips at 107 F, and the low alarm at 95 F. If you change the set point to 130 F, the alarms follow the set point and trip at 137 F and 125 F. Both process and deviation alarms can be latching or non-latching. When the alarm condition is removed a non-latching alarm automatically clears the alarm output. You must manually clear a latching alarm before it will disappear. Flashing 'LO" or "HI" in the lower display indicates an alarm. The lower display alternately shows information from the current parameter and the "LO" or "HI" alarm message at one second intervals. The alarm output is de-energized and the A1 or A2 LED is lit. To clear an alarm First correct the alarm condition, then If the alarm is latching Clear it manually; press AUTO/MAN once as soon as the process temperature is inside the alarm limit according to the HYSX parameter. If the alarm is non-latching The alarm will clear itself automatically as soon as the process temperature is inside the alarm limit according to the HYSX parameter. Press once - Clear a latched and corrected alarm. Figure 35 - Alarm Display Examples Alarm Silencing for alarm output A1 is available with the deviation alarm. This overrides alarm A1 during power up. The non-latching mode automatically enables alarm output A1 on initial power up. In the latching mode, manually disable the alarm by pressing AUTO/MAN once. In both cases alarm silencing disables the A1 alarm output relay, but the A1 LED displays the alarm condition until the process value is within the "safe" region of the deviation alarm band. Once the process value crosses into the "safe" region, both a latching or a nonlatching alarm is ready. Any future deviation outside this safe band triggers an alarm. Tuning and Operating, Chapter 5 WATLOW Series 945 User's Manual 25

26 Error Codes Error Code Messages ç Four dashes, " ", in the upper display indicate a Series 945 error. The error code is visible in the lower display. NOTE: An alarm display will be masked by an error condition or when the control is in the Calibration or Setup Menus. ç WARNING: Electrical noise or a noise event, vibration or excess environmental moisture or temperature may cause Series 945 errors to occur. If the cause of an error is not otherwise apparent, check for these. Er 1 - Sensor overrange error The sensor input generated a value higher than that allowed for the range of the sensor, or the A/D circuitry malfunctioned. Enter a valid input. The A/D value is above the range limits, but within the A/D conversion limits. Make sure the In parameter matches your sensor. Er 2 - Sensor underrange error The sensor input generated a value lower than that allowed for the range of the sensor, or the A/D circuitry malfunctioned. Enter a valid input. The A/D value is below the range limits, but within the A/D conversion limits. Make sure the In parameter matches your sensor. Er 3 - Ambient error Check the specification for the ambient temperature range. Er 4 - Configuration error The unit's microprocessor is faulty; call the factory. Er 5 - Non volatile checksum error The nonvolatile memory checksum discovered a checksum error. Unless a momentary power interruption occurred while the unit was storing data, the nonvolatile memory is bad. Call the factory. Er 6 - A/D underflow error The A/D circuit is underrange. An open or reversed polarity sensor is the most likely cause. Check the sensor; if the connection is good, and functions properly, call the factory. The A/D underrange voltage is too low to convert an A/D signal. Make sure the In parameter matches your sensor. Er 7 - A/D overflow error The A/D circuit is overrange. An open or reversed polarity sensor is the most likely cause. Check the sensor; if the connection is good, and functions properly, call the factory. The A/D overrange voltage is too high to convert an A/D signal. Make sure the In parameter matches your sensor. 26 WATLOW Series 945 User's Manual Tuning and Operating, Chapter 5

27 Error Codes Error Code Actions Error codes Er 1, Er 2, Er 3, Er 6, or Er 7 will result in these conditions: If operator access is LOC 0 or 1 and the control was in AUTO operation when the error occurred, it goes into manual % power operation. If the output power is less than 75% power, and a <5% change in power occurred within the last two minutes, the 945 switches into manual operation at the last automatic power level bumpless transfer. If the control was in manual operation, it remains there. Press AUTO/MAN twice to see the error code. The alarm output if present is in its alarm state LED lit. The upper display reads " ". The lower display indicates the error code. If the control was operating with stable output values when the error occurred, it continues to operate at those levels on a % power basis. If output values were not stable, the control outputs go to 0% power OFF. If operator access is LOC 2 or 3 The control remains in AUTO operation and the outputs go OFF. AUTO/MAN and MODE are inactive. The UP/DOWN keys may be used simultaneously to enter the Setup Menu. The alarm output if present is in its alarm state LED lit. The Upper display reads " ". The Lower display indicates the error code. To clear a corrected error Cycle power or MODE through Setup until you return to the set point. Error codes Er 4 or Er 5 will result in these conditons: The control is in AUTO operation with both outputs OFF. The alarm outputs are in their alarm state de-energized with the LED lit. The upper display indicates the process value. The lower display indicates the error code. All keys are inactive. All Setup Menu parameters return to default values. The above conditions occur regardless of the LOC value, or the presence of the Setup or Calibration Menus. To clear a corrected error Cycle power to the control. Tuning and Operating, Chapter 5 WATLOW Series 945 User's Manual 27